The Role Of Edaphic Environment And Climate In Structuring Phylogenetic Pattern In Seasonally Dry Tropical Plant Communities.

Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability (edaphic environment and climate) in the Caatinga, a SDTF in Brazil. Caatinga is characterized by semiarid climate and three distinct edaphic environments - sedimentary, crystalline, and inselberg -representing a decreasing gradient in soil water availability. We used two measures of phylogenetic diversity: Net Relatedness Index based on the entire phylogeny among species present in a site, reflecting long-term diversification; and Nearest Taxon Index based on the tips of the phylogeny, reflecting more recent diversification. We also evaluated woody species in contrast to herbaceous species. The main climatic variable influencing phylogenetic pattern was precipitation in the driest quarter, particularly for herbaceous species, suggesting that environmental filtering related to minimal periods of precipitation is an important driver of Caatinga biodiversity, as one might expect for a SDTF. Woody species tended to show phylogenetic clustering whereas herbaceous species tended towards phylogenetic overdispersion. We also found phylogenetic clustering in two edaphic environments (sedimentary and crystalline) in contrast to phylogenetic overdispersion in the third (inselberg). We conclude that while niche conservatism is evident in phylogenetic clustering in the Caatinga, this is not a universal pattern likely due to heterogeneity in the degree of realized environmental filtering across edaphic environments. Thus, SDTF, in spite of a strong shared environmental filter, are potentially heterogeneous in phylogenetic structuring. Our results support the need for scientifically informed conservation strategies in the Caatinga and other SDTF regions that have not previously been prioritized for conservation in order to take into account this heterogeneity.

Nanoparticles Applied To Plant Science: A Review.

The present review addresses certain important aspects regarding nanoparticles and the environment, with an emphasis on plant science. The production and characterization of nanoparticles is the focus of this review, providing an idea of the range and the consolidation of these aspects in the literature, with modifications on the routes of synthesis and the application of the analytical techniques for characterization of the nanoparticles (NPs). Additionally, aspects related to the interaction between the NPs and plants, their toxicities, and the phytoremediation process, among others, are also discussed. Future trends are also presented, supplying evidence for certain possibilities regarding new research involving nanoparticles and plants.

Mineral Nutrition Of Campos Rupestres Plant Species On Contrasting Nutrient-impoverished Soil Types.

In Brazil, the campos rupestres occur over the Brazilian shield, and are characterized by acidic nutrient-impoverished soils, which are particularly low in phosphorus (P). Despite recognition of the campos rupestres as a global biodiversity hotspot, little is known about the diversity of P-acquisition strategies and other aspects of plant mineral nutrition in this region. To explore nutrient-acquisition strategies and assess aspects of plant P nutrition, we measured leaf P and nitrogen (N) concentrations, characterized root morphology and determined the percentage arbuscular mycorrhizal (AM) colonization of 50 dominant species in six communities, representing a gradient of soil P availability. Leaf manganese (Mn) concentration was measured as a proxy for carboxylate-releasing strategies. Communities on the most P-impoverished soils had the highest proportion of nonmycorrhizal (NM) species, the lowest percentage of mycorrhizal colonization, and the greatest diversity of root specializations. The large spectrum of leaf P concentration and variation in root morphologies show high functional diversity for nutritional strategies. Higher leaf Mn concentrations were observed in NM compared with AM species, indicating that carboxylate-releasing P-mobilizing strategies are likely to be present in NM species. The soils of the campos rupestres are similar to the most P-impoverished soils in the world. The prevalence of NM strategies indicates a strong global functional convergence in plant mineral nutrition strategies among severely P-impoverished ecosystems.

New Fefe-hydrogenase Genes Identified In A Metagenomic Fosmid Library From A Municipal Wastewater Treatment Plant As Revealed By High-throughput Sequencing.

A fosmid metagenomic library was constructed with total community DNA obtained from a municipal wastewater treatment plant (MWWTP), with the aim of identifying new FeFe-hydrogenase genes encoding the enzymes most important for hydrogen metabolism. The dataset generated by pyrosequencing of a fosmid library was mined to identify environmental gene tags (EGTs) assigned to FeFe-hydrogenase. The majority of EGTs representing FeFe-hydrogenase genes were affiliated with the class Clostridia, suggesting that this group is the main hydrogen producer in the MWWTP analyzed. Based on assembled sequences, three FeFe-hydrogenase genes were predicted based on detection of the L2 motif (MPCxxKxxE) in the encoded gene product, confirming true FeFe-hydrogenase sequences. These sequences were used to design specific primers to detect fosmids encoding FeFe-hydrogenase genes predicted from the dataset. Three identified fosmids were completely sequenced. The cloned genomic fragments within these fosmids are closely related to members of the Spirochaetaceae, Bacteroidales and Firmicutes, and their FeFe-hydrogenase sequences are characterized by the structure type M3, which is common to clostridial enzymes. FeFe-hydrogenase sequences found in this study represent hitherto undetected sequences, indicating the high genetic diversity regarding these enzymes in MWWTP. Results suggest that MWWTP have to be considered as reservoirs for new FeFe-hydrogenase genes.

Insect mortality in Spathodea campanulata Beauv. (Bignoniaceae) flowers

537

Preparative separation of flavonoids from the medicinal plant Davilla elliptica St. Hill. by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) is a major tool for the fast separation of natural products from plants. It was used for the preparative isolation of the flavonoid monoglucosides present in the aerial parts of the Davilla elliptica St. Hill. (Dilleniaceae). This species is used in Brazilian folk medicine for the treatment of gastric disorders. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80, v/v/v) and led to a successful separation of quercetin-3-O-alpha-L-rhamnopyranoside and myricetin-3-O-alpha-L-rhamnopyranoside in approximately 3.0 hours with purity higher than 95%. Identification was performed by ¹H NMR, 13C NMR and HPLC-UV-DAD analyses.

Estimativa de parâmetros biofísicos de plantios de café a partir de imagens orbitais de alta resolução espacial

Remote sensing data are each time more available and can be used to monitor the vegetal development of main agricultural crops, such as the Arabic coffee in Brazil, since that the relationship between spectral and agronomical data be well known. Therefore, this work had the main objective to assess the use of Quickbird satellite images to estimate biophysical parameters of coffee crop. Test area was composed by 25 coffee fields located between the cities of Ribeirão Corrente, Franca and Cristais Paulista (SP), Brazil, and the biophysical parameters used were row and between plants spacing, plant height, LAI, canopy diameter, percentage of vegetation cover, roughness and biomass. Spectral data were the reflectance of four bands of QUICKBIRD and values of four vegetations indexes (NDVI, GVI, SAVI and RVI) based on the same satellite. All these data were analyzed using linear and nonlinear regression methods to generate estimation models of biophysical parameters. The use of regression models based on nonlinear equations was more appropriate to estimate parameters such as the LAI and the percentage of biomass, important to indicate the productivity of coffee crop.

The relationship between physical aspects of quality of life and extreme levels of regular physical activity in adults

This study aimed to check for any significant differences in perceived quality of life, specifically aspects of a physical nature, among volunteers who are more physically active and those less physically active in a university community. The sample consisted of 1,966 volunteers in a university community in Brazil. To assess physical activity levels, volunteers responded to the International Physical Activity Questionnaire (IPAQ), and to analyse the perception of quality of life they responded to WHOQOL-bref, which is classified into three groups according to level of physical activity, taking into account the metabolic equivalent index (MET) over a full week. For comparison, consideration was given to the first and third tertiles, respectively, namely groups of more and less active students. The results indicated that individuals who engaged in more physical activity had a more positive perception of quality of life compared to those who were less active in physical aspects related to the ability to work, energy for day-to-day activities and locomotion.

Dispersão de sementes de Vismia cayennensis (Jacq.) Pers. (Guttiferae) por morcegos na região de Manaus, Amazonas

We studied the feeding behavior of bats and their role in the seed dispersal of Vismia cayennensis in Manaus region, Amazonas State, northern Brazil. The characteristics of the plant and its fruits fit the chiropterocory syndrome. Five species of phyllostomid bats fed on Vismia fruits: Sturnira lilium, Sturnira tildae, Artibeus concolor, Carollia perspicillata and Rhinophylla pumilio. Apparently there is a relationship between flock foraging behavior and fruit availability in early night. The feeding behavior was similar for all bat species, varying with the presentation mode of the fruits. Seed germination tests and the distributional patterns of the plants indicate that bats are the dispersers of V. cayennensis.

Two mistletoes are too many?: Interspecific occurrence of mistletoes on the same host tree

Mistletoe can have a major impact on the fitness of the host plant. If there is more than one species of mistletoe on the same host tree, the overall impact might be amplified. We report the occurrence of more than one species of mistletoe on the same host tree. Although it is not a rule in the field, to our knowledge, there have been no studies of this topic. In most cases, two species of mistletoe were recorded on the same host tree, although we recorded three species of mistletoe on one occasion. This demonstrates that different species of mistletoe can be compatible with the same host species. Therefore, compatibility (structural and physiological) might be an important factor for the occurrence of mistletoe. Recent studies have shown that if the mistletoe does not recognize the host species, the deposited seeds will germinate but the haustorium will not penetrate the host branch. This is probably the primary mechanism in the establishment of more than one species of mistletoe on the same host, which can trigger a cascade of harmful effects for the host species.

Tissue culture of Cecropia glaziovii Sneth (urticaceae): vegetative micropropagation and plant regeneration from callus

Cecropia glaziovii is a tree with used in Brazilian popular medicine. Methods allowing the clonal propagation of this species are of great interest for superior genotype multiplication and perpetuation. For this reason, we examined the effect of different culture media and different types of explants on adventitious shoot regeneration from callus and buds of C. glaziovii. Leaves, petioles and stipules obtained from aseptically grown seedlings or from pre-sterilized plants were used to initiate cultures. Adventitious shoot regeneration was achieved when apical and axillary buds were inoculated on gelled Murashige & Skoog (MS) medium supplemented with 6-benzylaminopurine alone (BAP) (1.0, 5.0 or 10.0 mg L-1) or combined with -naphthalene acetic acid (NAA) (1.0 or 2.0 mg L-1), after 40 days of culture. Best callus production was obtained after 30 days of petioles' culture on gelled MS medium with 2,4 dichlorophenoxyacetic acid (2,4-D) (5.0 mg L-1) combined with BAP (1.0 mg L-1). Successful shoot regeneration from callus was achieved when MS medium supplemented with zeatin (ZEA) (0.1 mg L-1) alone or combined with 2,4-D (1.0 or 5.0 mg L-1) was inoculated with friable callus obtained from petioles. All shoots were rooted by inoculation on MS medium supplemented with indole-3-acetic acid (IAA) (1.0 mg L-1). Rooted plants transferred to potting soil were successfully established. All in vitro regenerated plantlets showed to be normal, without morphological variations, being also identical to the source plant. Our study has shown that C. glaziovii can be propagated by tissue culture methods, allowing large scale multiplication of superior plants for pharmacological purposes.